Since Microsoft designed Windows 8 with the world of always-on tablets in mind, the company thinks you'll need to shut down and restart so rarely that these functions are buried in the menu structure. In Windows 7, the Shut Down button is displayed prominently on the Start menu, whereas in Windows 8, the suggested method is to pull out the Charms menu, click the Settings charm, click the Power button and then select Shut Down from a menu.
If you don't have time and shoulder muscles to waste, you can create your own shortcuts for both the Shut Down and Restart functions. Just assign the shortcuts to the command-line commands "shutdown /s /t 0" (shutdown) and "shutdown /r /t 0" (restart), respectively. Be sure to pin these shortcuts to the Start screen and taskbar for easy access.